Coloring agents for keratin fibers containing (1,1′-biphenyl)-2,4-diamine derivatives in addition to novel (1,1′-biphenyl)-2,4-diamine-derivatives

ABSTRACT

Keratin fiber coloring agents containing (1,1′-biphenyl)-2,4-diamine derivatives of general formula (I) or a physiologically tolerated salt thereof 
                         
and novel (1,1′-biphenyl)-2,4-diamine derivatives.

BACKGROUND OF THE INVENTION

1. Field of the Invention.

The present invention relates to agents for oxidative dyeing of keratinfibers, particularly human hair, based on a developer/couplercombination which contains a (1,1′-biphenyl)-2,4-diamine derivative asthe coupler, and to new (1,1′-biphenyl)-2,4-diamine derivatives.

2. Description of the Related Art.

In the area of keratin fiber dyeing, particularly hair dyeing, oxidationdyes have attained substantial importance. In this case, the colorationis produced by reaction of certain developers with certain couplers inthe presence of an appropriate oxidant. Suitable developers are, inparticular, 2,5-diaminotoluene, 2,5-diaminophenylethyl alcohol,p-aminophenol, 4,5-diamino-1-(2′-hydroxyethyl)pyrazole and1,4-diamino-benzene, and suitable couplers are, for example, resorcinol,2-methylresorcinol, 1-naphthol, 3-aminophenol, m-phenylenediamine,2-amino-4-(2′-hydroxyethyl)amino-anisole,1,3-diamino-4-(2′-hydroxyethoxy)benzene and 2,4-diamino-5-fluorotoluene.

The oxidation dyes used for dyeing human hair must meet numerousrequirements in addition to that of being able to produce colorations ofthe desired intensity. For example, these dyes must be harmless from atoxicological and dermatological standpoint, and the hair colorationsobtained must have good light fastness, resistance to permanent waving,acid fastness and rubbing fastness. In any case, however, in the absenceof exposure to light, rubbing and chemicals, such colorations mustremain stable over a period of at least 4 to 6 weeks. Moreover, bycombining appropriate developers and couplers, it must be possible tocreate a wide range of different color shades.

Attempts have already been made to improve the properties ofm-phenylenediamines by introduction of substituents. In this regard, thereader is referred to German Unexamined Patent Application DE 30 28 131which, among other things, also describes dyeing agents which ascouplers contain special m-phenylenediamines alkyl-substituted in the4-position.

With the currently known dyeing agents, however, it is not possible tomeet the requirements placed on such agents in all respects. Hence, theneed continued to exist for novel couplers that would meet the aforesaidrequirements to a particularly high degree.

SUMMARY OF THE INVENTION

We have now found that by use of (1,1′-biphenyl)-2,4-diamine derivativesof general formula (I) intense, stable blue color shades can be obtainedin addition to natural and purple or violet shades.

Hence, the object of the present invention is an agent for oxidativedyeing of keratin fibers, for example wool, furs, feathers or hair,particularly human hair, which agent is based on a developer-couplercombination that is characterized by the fact that it contains as thecoupler at least one (1,1′-biphenyl)-2,4-diamine derivative of formula(I) or a physiologically tolerated salt thereof

wherein

-   R1, R2, R3, R4 and R5 can be equal or different and independently of    each other denote hydrogen, a halogen atom (fluorine, chlorine,    bromine, iodine), a cyano group, a hydroxyl group, a C₁–C₄-alkoxy    group, a C₁–C₄-hydroxyalkoxy group. a C₁–C₆-alkyl group, a    C₁–C₄-alkyl thioether group, a mercapto group, a nitro group, an    amino group (NH₂), a C₁–C₄-monoalkylamino group, a    di(C₁–C₄)-alkylamino group, a trifluoromethyl group, a —C(O)H group,    a —C(O)CH₃ group, a —C(O)CF₃ group, an —Si(CH₃)₃ group, a    C₁–C₄-hydroxyalkyl group, a C₂–C₄-dihydroxyalkyl group, a —CH═CHR6    group, a —(CH₂)_(p)—CO₂R7 group or a —(CH₂)_(p)—R8 group with p=1,    2, 3 or 4, a —C(R9)=NR10 group or a C(R12)H—NR13R14 group, or two    adjacent R1 to R5 groups form an —O—CH₂—O bridge;-   R6 denotes hydrogen, a nitro group, a CO₂R7 group or a —C(O)CH₃    group;-   R7, R9 and R12 can be equal or different and independently of each    other denote hydrogen or a C₁–C₄-alkyl group;-   R8 denotes an amino or nitrile group;-   R10, R13 and R14 can be equal or different and independently of each    other denote hydrogen, a hydroxyl group, a C₁–C₄-alkyl group, a    C₁–C₄-hydroxyalkyl group, a C₂–C₄-dihydroxyalkyl group or a group of    formula

-   and R11 denotes hydrogen, an amino group or a hydroxyl group.

Noteworthy among the compounds of formula (I) are, for example:

-   biphenyl-2,4-diamine; 4-benzo[1,3]dioxol-5-ylbenzene-1,3-diamine;    2′-(2-hydroxyethyl)biphenyl-2,4-diamine;    2′-acetylbiphenyl-2,4-diamine; 2′-aminobiphenyl-2,4-diamine;    2′-bromobiphenyl-2,4-diamine; 2′-chlorobiphenyl-2,4-diamine;    2′-cyanobiphenyl-2,4-diamine; 2′-ethylbiphenyl-2,4-diamine;    2′-fluorobiphenyl-2,4-diamine; 2′-hydroxybiphenyl-2,4-diamine;    2′-methoxybiphenyl-2,4-diamine; 2′-methylbiphenyl-2,4-diamine;    2′-methylsulfanylbiphenyl-2,4-diamine; 2′-nitrobiphenyl-2,4-diamine;    2′-trifluoromethylbiphenyl-2,4-diamine;    3′-(2-hydroxyethyl)biphenyl-2,4-diamine;    3′-acetylbiphenyl-2,4-diamine; 3′-aminobiphenyl-2,4-diamine;    3′-bromobiphenyl-2,4-diamine; 3′-chlorobiphenyl-2,4-diamine;    3′-cyanobiphenyl-2,4-diamine; 3′-ethylbiphenyl-2,4-diamine;    3′-fluorobiphenyl-2,4-diamine; 3′-hydroxybiphenyl-2,4-diamine;    3′-methoxybiphenyl-2,4-diamine; 3′-methylbiphenyl-2,4-diamine;    3′-methylsulfanylbiphenyl-2,4-diamine; 3′-nitrobiphenyl-2,4-diamine;    3′-trifluoromethylbiphenyl-2,4-diamine;    4′-(2-hydroxyethyl)biphenyl-2,4-diamine;    4′-acetylbiphenyl-2,4-diamine; 4′-aminobiphenyl-2,4-diamine;    4′-bromobiphenyl-2,4-diamine; 4′-chlorobiphenyl-2,4-diamine;    4′-cyanobiphenyl-2,4-diamine; 4′-ethylbiphenyl-2,4-diamine;    4′-fluorobiphenyl-2,4-diamine; 4′-hydroxybiphenyl-2,4-diamine;    4′-methoxybiphenyl-2,4-diamine; 4′-methylbiphenyl-2,4-diamine;    4′-methylsulfanylbiphenyl-2,4-diamine; 4′-nitrobiphenyl-2,4-diamine;    4′-trifluoromethylbiphenyl-2,4-diamine;    2′-amino-3′-aminobiphenyl-2,4-diamine;    2′-amino-3′-hydroxybiphenyl-2,4-diamine;    2′-amino-3′-methoxybiphenyl-2,4-diamine;    2′-amino-3′-methylbiphenyl-2,4-diamine;    2′-amino-4′-aminobiphenyl-2,4-diamine;    2′-amino-4′-hydroxybiphenyl-2,4-diamine;    2′-amino′-4′-methoxybiphenyl-2,4-diamine;    2′-amino-4′-methylbiphenyl-2,4-diamine;    2′-amino-5′-aminobiphenyl-2,4-diamine;    2′-amino-5′-hydroxybiphenyl-2,4-diamine;    2′-amino-5′-methoxybiphenyl-2,4-diamine;    2′-amino-5′-methylbiphenyl-2,4-diamine;    2′-amino-6′-aminobiphenyl-2,4-diamine;    2′-amino-6′-hydroxybiphenyl-2,4-diamine;    2′-amino-6′-methoxybiphenyl-2,4-diamine;    2′-amino-6′-methylbiphenyl-2,4-diamine;    2′-hydroxy-3′-aminobiphenyl-2,4-diamine;    2′-hydroxy-3′-hydroxybiphenyl-2,4-diamine;    2′-hydroxy-3′-methoxybiphenyl-2,4-diamine;    2′-hydroxy-3′-methylbiphenyl-2,4-diamine;    2′-hydroxy-4′-aminobiphenyl-2,4-diamine;    2′-hydroxy-4′-hydroxybiphenyl-2,4-diamine;    2′-hydroxy-4′-methoxybiphenyl-2,4-diamine;    2′-hydroxy-4′-methylbiphenyl-2,4-diamine;    2′-hydroxy-5′-aminobiphenyl-2,4-diamine;    2′-hydroxy-5′-hydroxybiphenyl-2,4-diamine;    2′-hydroxy-5′-methoxybiphenyl-2,4-diamine;    2′-hydroxy-5′-methylbiphenyl-2,4-diamine;    2′-hydroxy-6′-aminobiphenyl-2,4-diamine;    2′-hydroxy-6′-hydroxybiphenyl-2,4-diamine;    2′-hydroxy-6′-methoxybiphenyl-2,4-diamine;    2′-hydroxy-6′-methylbiphenyl-2,4-diamine;    2′-methoxy-3′-aminobiphenyl-2,4-diamine;    2′-methoxy-3′-hydroxybiphenyl-2,4-diamine;    2′-methoxy-3′-methoxybiphenyl-2,4-diamine;    2′-methoxy-3′-methylbiphenyl-2,4-diamine;    2′-methoxy-4′-aminobiphenyl-2,4-diamine;    2′-methoxy-4′-hydroxybiphenyl-2,4-diamine;    2′-methoxy-4′-methoxybiphenyl-2,4-diamine;    2′-methoxy-4′-methylbiphenyl-2,4-diamine;    2′-methoxy-5′-aminobiphenyl-2,4-diamine;    2′-methoxy-5′-hydroxybiphenyl-2,4-diamine;    2′-methoxy-5′-methoxybiphenyl-2,4-diamine;    2′-methoxy-5′-methylbiphenyl-2,4-diamine;    2′-methoxy-6′-aminobiphenyl-2,4-diamine;    2′-methoxy-6′-hydroxybiphenyl-2,4-diamine;    2′-methoxy-6′-methoxybiphenyl-2,4-diamine;    2′-methoxy-6′-methylbiphenyl-2,4-diamine;    2′-methyl-3′-aminobiphenyl-2,4-diamine;    2′-methyl-3′-hydroxybiphenyl-2,4-diamine;    2′-methyl-3′-methoxybiphenyl-2,4-diamine;    2′-methyl-3′-methylbiphenyl-2,4-diamine;    2′-methyl-4′-aminobiphenyl-2,4-diamine;    2′-methyl-4′-hydroxybiphenyl-2,4-diamine;    2′-methyl-4′-methoxybiphenyl-2,4-diamine;    2′-methyl-4′-methylbiphenyl-2,4-diamine;    2′-methyl-5′-aminobiphenyl-2,4-diamine;    2′-methyl-5′-hydroxybiphenyl-2,4-diamine;    2′-methyl-5′-methoxybiphenyl-2,4-diamine;    2′-methyl-5′-methylbiphenyl-2,4-diamine;    2′-methyl-6′-aminobiphenyl-2,4-diamine;    2′-methyl-6′-hydroxybiphenyl-2,4-diamine;    2′-methyl-6′-methoxybiphenyl-2,4-diamine;    2′-methyl-6′-methylbiphenyl-2,4-diamine;    3′-amino-4′-aminobiphenyl-2,4-diamine;    3′-amino-4′-hydroxybiphenyl-2,4-diamine;    3′-amino-4′-methoxybiphenyl-2,4-diamine;    3′-amino-4′-methylbiphenyl-2,4-diamine;    3′-amino-5′-aminobiphenyl-2,4-diamine;    3′-amino-5′-hydroxybiphenyl-2,4-diamine;    3′-amino-5′-methoxybiphenyl-2,4-diamine;    3′-amino-5′-methylbiphenyl-2,4-diamine;    3′-hydroxy-4′-aminobiphenyl-2,4-diamine;    3′-hydroxy-4′-hydroxy-biphenyl-2,4-diamine;    3′-hydroxy-4′-methoxybiphenyl-2,4-diamine;    3′-hydroxy-4′-methylbiphenyl-2,4-diamine;    3′-hydroxy-5′-aminobiphenyl-2,4-diamine;    3′-hydroxy-5′-hydroxybiphenyl-2,4-diamine;    3′-hydroxy-5′-methoxybiphenyl-2,4-diamine;    3′-hydroxy-5′-methylbiphenyl-2,4-diamine;    3′-methoxy-4′-aminobiphenyl-2,4-diamine;    3′-methoxy-4′-hydroxybiphenyl-2,4-diamine;    3′-methoxy-4′-methoxybiphenyl-2,4-diamine;    3′-methoxy-4′-methylbiphenyl-2,4-diamine;    3′-methoxy-5′-aminobiphenyl-2,4-diamine;    3′-methoxy-5′-hydroxybiphenyl-2,4-diamine;    3′-methoxy-5′-methoxybiphenyl-2,4-diamine;    3′-methoxy-5′-methylbiphenyl-2,4-diamine;    3′-methyl-4′-aminobiphenyl-2,4-diamine;    3′-methyl-4′-hydroxybiphenyl-2,4-diamine;    3′-methyl-4′-methoxybiphenyl-2,4-diamine;    3′-methyl-4′-methylbiphenyl-2,4-diamine;    3′-methyl-5′-aminobiphenyl-2,4-diamine;    3′-methyl-5′-hydroxybiphenyl-2,4-diamine;    3′-methyl-5′-methoxybiphenyl-2,4-diamine and    3′-methyl-5′-methylbiphenyl-2,4-diamine, as well as the    physiologically tolerated salts thereof.

Preferred compounds of formula (I) or their physiologically toleratedsalts are those wherein (i) at least three of the R1 to R5 groups denotehydrogen or (ii) three of the R1 to R5 groups denote hydrogen and thetwo remaining groups independently of each other denote hydrogen, amethoxy group, a hydroxyl group, a C₁–C₄-alkyl group, aC₁–C₄-hydroxyalkyl group or an amino group, or when the two remaininggroups are adjacent to each other they together form an —O—CH₂—O—bridge.

Particularly preferred are the following (1,1′-biphenyl)-2,4-diaminederivatives of formula (I): biphenyl-2,4-diamine;4-benzo[1,3]dioxol-5-ylbenzene-1,3-diamine;4′-hydroxybiphenyl-2,4-diamine; 4′-aminobiphenyl-2,4-diamine;3′-hydroxybiphenyl-2,4-diamine; 4′-methoxybiphenyl-2,4-diamine and thephysiologically tolerated salts thereof.

The compounds of formula (I) can be used as the free bases as well as inthe form of their physiologically tolerated salts with inorganic ororganic acids, for example hydrochloric acid, sulfuric acid, phosphoricacid, acetic acid, propionic acid, lactic acid or citric acid.

The colorant of the invention contains the (1,1′-biphenyl)-2,4-diaminederivatives of formula (I) in a total amount from about 0.005 to 20 wt.%, an amount of about 0.01 to 5 wt. % and especially 0.1 to 2.5 wt. %being preferred.

Suitable developers are all those developers that are known to be usedwith, and are appropriate for, such colorants, for example1,4-diaminobenzene (p-phenylenediamine), 1,4-diamino-2-methylbenzene(p-toluylenediamine), 1,4-diamino-2,6-dimethylbenzene,1,4-diamino-3,5-diethylbenzene, 1,4-diamino-2,5-dimethylbenzene,1,4-diamino-2,3-dimethylbenzene, 2-chloro-1,4-diaminobenzene,1,4-diamino-2-(thiophen-2-yl)benzene,1,4-diamino-2-(thiophen-3-yl)benzene,1,4-diamino-2-(pyridin-3-yl)benzene, 2,5-diaminobiphenyl;1,4-diamino-2-methoxymethylbenzene, 1,4-diamino-2-aminomethylbenzene,1,4-diamino-2-hydroxymethylbenzene,1,4-diamino-2-(2-hydroxyethoxy)benzene, 1-(2,5-diaminophenyl)ethanol,2-[2-(acetylamino)ethoxy]-1,4-diaminobenzene, 4-phenylaminoaniline,4-dimethylaminoaniline, 4-diethylaminoaniline, 4-dipropylaminoaniline,4-[ethyl-(2-hydroxyethyl)amino]aniline,4-[di(2-hydroxyethyl)amino]aniline,4-[di(2-hydroxyethyl)amino]-2-methylaniline,4-[(2-methoxyethyl)amino]aniline, 4-[(3-hydroxypropyl)amino]aniline,4-[(2,3-dihydroxypropyl)amino]aniline,1,4-diamino-2-(2-hydroxyethyl)benzene,1,4-diamino-2-(1-methylethyl)benzene,1,3-bis-[(4-aminophenyl)(2-hydroxyethyl)amino]-2-propanol,1,4-bis-[(4-aminophenyl)amino]butane,1,8-bis-(2,5-diaminophenoxy)-3,6-dioxaoctane, 4-aminophenol,4-amino-3-methylphenol, 4-amino-3-(hydroxymethyl)phenol,4-amino-3-fluorophenol, 4-methylaminophenol,4-amino-2-(aminomethyl)phenol, 4-amino-2-(hydroxymethyl)phenol,4-amino-2-fluorophenol, 4-amino-2-[(2-hydroxyethyl)amino]-methylphenol,4-amino-2-methylphenol, 4-amino-2-(methoxymethyl)phenol,4-amino-2-(2-hydroxyethyl)phenol, 5-aminosalicylic acid,2,5-diaminopyridine, 2,4,5,6-tetraaminopyrimidine,2,5,6-triamino-4-(1H)-pyrimidone,4,5-diamino-1-(2-hydroxyethyl)-1H-pyrazole,4,5-diamino-1-(1-methylethyl)-1H-pyrazole,4,5-diamino-1-[(4-methylphenyl)methyl]-1H-pyrazole,1-[(4-chlorophenyl)methyl]-4,5-diamino-1H-pyrazole,4,5-diamino-1-methyl-1H-pyrazole,4,5-diamino-3-methyl-1-methyl-1H-pyrazole,4,5-diamino-3-methyl-1-methyl-1H-pyrazole[sic-Translator],2-aminophenol, 2-amino-6-methylphenol and 2-amino-5-methylphenol.

Moreover, the colorant of the invention can optionally also containother known couplers, for example 2,6-diaminopyridine,2-amino-4-[(2-hydroxyethyl)amino]anisole,2,4-diamino-1-fluoro-5-methylbenzene,2,4-diamino-1-methoxy-5-methylbenzene,2,4-diamino-1-ethoxy-5-methylbenzene,2,4-diamino-1-(2-hydroxyethoxy)-5-methylbenzene,2,4-di[(2-hydroxyethyl)amino]-1,5-dimethoxybenzene,2,3-diamino-6-methoxypyridine,3-amino-6-methoxy-2-(methylamino)pyridine,2,6-diamino-3,5-dimethoxypyridine, 3,5-diamino-2,6-dimethoxypyridine,1,3-diaminobenzene, 2,4-diamino-1-(2-hydroxyethoxy)benzene,2,4-diamino-1,5-di(2-hydroxyethoxy)benzene,1-(2-aminoethoxy)-2,4-diaminobenzene,2-amino-1-(2-hydroxyethoxy)-4-methylaminobenzene,2,4-diaminophenoxyacetic acid, 3-[di(2-hydroxyethyl)amino]aniline,4-amino-2-di[(2-hydroxyethyl)amino]-1-ethoxybenzene,5-methyl-2-(1-methylethyl)phenol, 3-[(2-hydroxyethyl)amino]aniline,3-[(2-aminoethyl)amino]aniline, 1,3-di(2,4-diaminophenoxy)propane,di(2,4-diaminophenoxy)methane, 1,3-diamino-2,4-dimethoxybenzene,2,6-bis-(2-hydroxyethyl)aminotoluene, 4-hydroxyindole,3-dimethylaminophenol, 3-diethylaminophenol, 5-amino-2-methylphenol,5-amino-4-fluoro-2-methylphenol, 5-amino-4-methoxy-2-methylphenol,5-amino-4-ethoxy-2-methylphenol, 3-amino-2,4-dichlorophenol,5-amino-2,4-dichlorophenol, 3-amino-2-methylphenol,3-amino-2-chloro-6-methylphenol, 3-aminophenol,2-[(3-hydroxyphenyl)amino]acetamide,5-[(2-hydroxyethyl)amino]-2-methylphenol,3-[(2-hydroxyethyl)amino]phenol, 3-[(2-methoxyethyl)amino]phenol,5-amino-2-ethylphenol, 2-(4-amino-2-hydroxyphenoxy)-ethanol,5-[(3-hydroxypropyl)amino]-2-methylphenol,3-[(2,3-dihydroxypropyl)amino]-2-methylphenol,3-[(2-hydroxyethyl)amino]-2-methylphenol, 2-amino-3-hydroxypyridine,5-amino-4-chloro-2-methylphenol, 1-naphthol, 1,5-dihydroxynaphthalene,1,7-dihydroxynaphthalene, 2,3-dihydroxynaphthalene,2,7-dihydroxynaphthalene, 2-methyl-1-naphthol acetate,1,3-di-hydroxybenzene, 1-chloro-2,4-dihydroxybenzene,2-chloro-1,3-dihydroxybenzene,1,2-dichloro-3,5-dihydroxy-4-methylbenzene,1,5-dichloro-2,4-dihydroxybenzene, 1,3-dihydroxy-2-methylbenzene,3,4-methylenedioxyphenol, 3,4-methylenedioxyaniline,5-[(2-hydroxyethyl)amino]-1,3-benzodioxole,6-bromo-1-hydroxy-3,4-methylenedioxybenzene, 3,4-diaminobenzoic acid,3,4-dihydro-6-hydroxy-1,4(2H)benzoxazine,6-amino-3,4-dihydro-1,4(2H)-benzoxazine, 3-methyl-1-phenyl-5-pyrazolone,5,6-dihydroxyindole, 5,6-dihydroxyindoline, 5-hydroxyindole,6-hydroxyindole, 7-hydroxyindole and 2,3-indolinedione.

The couplers and developers can be present in the colorant of theinvention either individually or in admixture with one another, thetotal amount of each of the couplers and developers in the colorant ofthe invention being about 0.005 to 20 wt. % preferably about 0.01 to 5.0wt. % and particularly 0.1 to 2.5 wt. % (based on the total amount ofcolorant). The total amount of the developer-coupler combinationcontained in the colorant described herein is preferably about 0.01 to20 wt. %, an amount of about 0.02 to 10 wt. % and especially 0.2 to 6wt. % being particularly preferred. In general, the developer and thecoupler are used in approximately equimolar amounts. In this respect, itis not disadvantageous, however, if the developer is present in acertain excess or deficiency [for example in a (coupler:developer) ratioof 1:2 to 1:0.5].

Moreover, the colorant of the invention can also contain other dyecomponents, for example 6-amino-2-methylphenol and2-amino-5-methylphenol, as well as common anionic, cationic, amphotericor nonionic direct dyes, for example triphenylmethane dyes such as4-[(4′-aminophenyl)-(4′-imino-2″,5″-cyclohexadien-1″-ylidene)methyl]-2-methylaminobenzenemonohydrochloride (Color Index [C.I.]42 510) and4-[(4′-amino-3′-methylphenyl)-(4″-imino-3″-methyl-2″,5″-cyclohexadien-1″-ylidene)methyl]-2-methylaminobenzenemonohydrochloride (C.I. 42 520), aromatic nitro dyes such as4-(2′-hydroxyethyl)aminonitrotoluene, 2-amino-4,6-dinitrophenol,2-amino-5-(2′-hydroxyethyl)aminonitrobenzene,2-chloro-6-(ethylamino)-4-nitrophenol,4-chloro-N-(2-hydroxyethyl)-2-nitroaniline,5-chloro-2-hydroxy-4-nitroaniline, 2-amino-4-chloro-6-nitrophenol and1-(2′-ureidoethyl)amino-4-nitrobenzene, azo dyes such as, for example,sodium 6-[(4′-aminophenyl)azo]-5-hydroxynaphthalene-1-sulfonate (C.I. 14805) and disperse dyes, for example 1,4-diaminoanthraquinone and1,4,5,8-tetraaminoanthraquinone. The colorants of the invention cancontain the aforesaid dye components in an amount from about 0.1 to 4wt. %.

The couplers and developers as well as the other dye components,provided they are bases, can, of course, also be used in the form oftheir physiologically tolerated salts with organic or inorganic acids,for example hydrochloric acid or sulfuric acid, or—if they containaromatic OH groups—in the form of their salts with bases, for example asalkali metal phenoxides.

Moreover, if the colorants of the invention are to be used for coloringhair, they can also contain other common cosmetic additives, for exampleantioxidants such as ascorbic acid, thio-glycolic acid or sodiumsulfite, as well as perfume oils, complexing agents, wetting agents,emulsifiers, thickeners and hair-care agents.

The colorant of the invention can be in the form of, for example, asolution, particularly an aqueous or aqueous-alcoholic solution. Aparticularly preferred formulation form, however, is a cream, gel oremulsion. Such a composition consists of a mixture of the dye componentsand the usual additives employed for such compositions.

Common additives to solutions, creams, emulsions or gels are, forexample solvents such as water, lower aliphatic alcohols, for exampleethanol, propanol or isopropanol, glycerol or glycols such as1,2-propylene glycol, moreover wetting agents or emulsifiers from theclasses of anionic, cationic, amphoteric or nonionic surface-activeagents, for example fatty alcohol sulfates, ethoxylated fatty alcoholsulfates, alkylsulfonates, alkylbenzenesulfonates,alkyltrimethylammonium salts, alkylbetaines, ethoxylated fatty alcohols,ethoxylated nonylphenols, fatty acid alkanolamides and ethoxylated fattyesters, furthermore thickeners such as the higher fatty alcohols,starch, cellulose derivatives, petrolatum, paraffin oil and fatty acids,also hair-care agents such as cationic resins, lanolin derivatives,cholesterol, pantothenic acid and betaine. The said constituents areused in amounts commonly employed for such purposes, for example thewetting agents and emulsifiers at a concentration of about 0.5 to 30 wt.%, the thickeners in an amount from about 0.1 to 25 wt. % and thehair-care agents at a concentration from about 0.1 to 5 wt. %.

Depending on the composition, the colorant of the invention can beweakly acidic, neutral or alkaline. In particular, it has a pH of 6.5 to11.5. Adjustment to a basic pH is preferably done with ammonia, but itcan also be done with an organic amine, for example monoethanolamine andtriethanolamine, or with an inorganic base such as sodium hydroxide andpotassium hydroxide. Suitable for adjustment to an acidic pH areinorganic or organic acids, for example phosphoric acid, acetic acid,citric acid or tartaric acid.

For oxidative dyeing of hair, the afore-described colorant is mixed withan oxidant just before use, and the resulting mixture is applied to hairin an amount sufficient for the hair-dyeing treatment, in general about50 to 200 grams, depending on the hair fullness. The ready-to-useoxidative hair colorant obtained after mixing with the oxidantpreferably has a pH of 6.5 to 11.5.

Suitable oxidants for developing the hair coloration are mainly hydrogenperoxide or its products of addition to urea, melamine, sodium borate orsodium carbonate, in the form of a 3–12%, preferably 6% aqueoussolution, atmospheric oxygen also being suitable. When a 6% hydrogenperoxide solution is used as oxidant, the weight ratio of hair colorantto oxidant is from 5:1 to 1:2, but preferably 1:1. Larger amounts ofoxidant are used primarily at higher dye concentrations in the haircolorant or when stronger bleaching of the hair is wanted at the sametime. The mixture is allowed to act on the hair at 15 to 50° C. forabout 10 to 45 min, preferably 30 min, after which the hair is rinsedwith water and dried. Optionally, following this rinsing, the hair iswashed with a shampoo and optionally post-rinsed with a weak organicacid, for example citric acid or tartaric acid. The hair is then dried.

The colorants of the invention containing a (1,1′-biphenyl)-2,4-diaminederivative of formula (I) as coupler give hair colorations of excellentcolor stability, particularly in terms of light fastness, wash fastnessand rubbing fastness. As far as the dyeing properties are concerned, thehair colorants of the invention provide a wide range of different colorshades from blond to brown, purple, violet and even blue and black,depending on the developer-coupler combination used, the achievableintense and stable blue shades being particularly noterworthy. The verygood coloring properties of the hair colorant of the present patentapplication also manifest themselves in that this colorant makes itpossible to dye gray hair, previously not damaged chemically, withoutany problems and with good covering power.

The (1,1′-biphenyl)-2,4-diamine derivatives of formula (I) can beprepared by known methods of synthesis, for example by methods similarto those described in the practical examples given hereinbelow.

The (1,1′-biphenyl)-2,4-diamine derivatives of formula (I) are highlywater-soluble and give colorations—particularly in the blue and purplecolor range—of high color intensity and excellent color stability,particularly in terms of light fastness, wash fastness and rubbingfastness. Moreover, they have excellent storage stability, particularlyas constituents of the oxidation colorants described herein.

Hence, another object of the present invention are(1,1′-biphenyl)-2,4-diamine derivatives of general formula (II)

wherein

R1, R2, R3, R4, R5 can be equal or different and independently of eachother denote hydrogen, hydrogen[sic-Translator], a chlorine atom, afluorine atom, a cyano group, a hydroxyl group, a C₁–C₄-alkoxy group, aC₁–C₄-hydroxyalkoxy group, a C₁–C₆-alkyl group, a C₁–C₄-alkyl thioethergroup, a mercapto group, a nitro group, an amino group (NH₂), aC₁–C₄-monoalkylamino group, a di(C₁–C₄)-alkylamino group, atrifluoromethyl group, a —C(O)H group, a —C(O)CH₃ group, a —C(O)CF₃group, an —Si(CH₃)₃ group, a C₁–C₄-hydroxyalkyl group, aC₂–C₄-dihydroxyalkyl group, a —CH═CHR6 group, a —(CH₂)_(p)—CO₂R7 group,a —(CH₂)_(p)—R8 group with p=1, 2, 3 or 4, a —C(R9)=NR10 group or aC(R12)H—NR13R14 group, or two adjacent R1 to R5 groups form an —O—CH₂O—bridge;

-   -   R6 denotes hydrogen, a nitro group, a CO₂R7 group or a —C(O)CH₃        group;    -   R7, R9 and R12 can be equal or different and independently of        each other denote hydrogen or a C₁–C₄-alkyl group;    -   R8 denotes an amino group or a nitrile group;    -   R10, R13 and R14 can be equal or different and independently of        each other denote hydrogen, a hydroxyl group, a C₁–C₄-alkyl        group, a C₁–C₄-hydroxyalkyl group, a C₂–C₄-dihydroxyalkyl group        or a group having the formula

-   and R11 denotes hydrogen, an amino group or a hydroxyl group;-   and at least one of the R1 to R5 groups does not denote hydrogen,-   or the physiologically tolerated salts thereof.

The following examples illustrate the object of the invention in greaterdetail without limiting its scope.

EXAMPLES Example 1

A. Synthesis oftert.butyl(4-bromo-3-tert.butoxycarbonylaminophenyl)carbamate

To a suspension of 10 g (32.4 mmoles) oftert.butyl(3-tert.butoxycarbonylaminophenyl)carbamate in 100 mL of1,2-dimethoxyethane was added dropwise at 0° C. over a period of 2 hoursa solution of 6 g (33.7 mmoles) of N-bromosuccinimide in 50 mL of1,2-dimethoxyethane. The reaction mixture was then allowed to agitatefor an additional 2 hours. At the end of the reaction, the reactionmixture was poured into 300 mL of water which produced a precipitate.The precipitate was filtered off and washed with water.

This gave 11 g (94% of the theoretical) oftert.butyl(4-bromo-3-tert.butoxycarbonylaminophenyl)carbamate.

¹H-NMR (300 MHz, DMSO-D6): δ=9.51 (s, 1H); 8.43 (s, 1H); 7.89 (s, 1H);7.47 (d, 1H); 7.18 (d, 1H); 1.47 (d, 18H).

B. Synthesis oftert.butyl[3-tert.butoxycarbonylamino-4-(4,4,5,5-tetramethyl-[1,3,2]dioxa-2-borolanyl)phenyl]carbamate

210 mL of degassed dioxane was added under argon to a mixture of 7.8 g(20.2 mmoles) oftert.butyl(4-bromo-3-tert.butoxycarbonylaminophenyl)carbamate from stepA, 12.8 g (50.6 mmoles) of4,4,4′,4′,5,5,5,5′-octamethyl[2,2′]bi{[1,3,2]-dioxaborinanyl}, 2 g (2.9mmoles) ofdichloro-[1,1′-bis(diphenylphosphino)ferrocene]palladium[PdCl₂(dppf)]and 6.2 g (63.2 mmoles) of potassium acetate. The mixture was allowed toagitate 26 hours at 80° C. and to it was then added a mixture of 4.2 g(16.9 mmoles) of diboronpinacole ester and 700 mg (0.95 mmole) ofPdCl₂(dppf). The reaction mixture was then allowed to agitate for anadditional 14 hours at 80° C. after which it was poured into water andextracted with ethyl acetate. The organic phase was washed with asaturated aqueous sodium chloride solution, dried over sodium sulfateand filtered, and the filtrate was evaporated. The resulting crudeproduct was purified on deactivated silica gel with hexane/ethyl acetate(1:1).

This gave 6.20 g (71% of the theoretical) oftert.butyl[3-tert.butoxycarbonylamino-4-(4,4,5,5-tetramethyl[1,3,2]dioxa-2-borolanyl)phenyl]carbamate.

C. Synthesis of (1,1′-biphenyl)-2,4-diamines

0.09 g (0.0002 mole) oftert.butyl[3-tert.butoxycarbonylamino-4-(4,4,5,5-tetramethyl-[1,3,2]dioxa-2-borolanyl)phenyl]carbamatefrom step B and 0.0004 mole of the appropriate bromo derivative weredissolved in 10 mL of 1,2-dimethoxyethane under argon. Then, 0.01 g(0.000005 mole) of tetrakis(triphenylphosphine)palladium and 0.26 mL of2N potassium carbonate solution were added, and the reaction mixture washeated to 80° C. At the end of the reaction, the reaction mixture waspoured into 10 mL of ethyl acetate and the organic phase was extractedwith dilute sodium hydroxide and dried with magnesium sulfate. Thesolvent was distilled off in a rotary evaporator, and the residue waspurified on silica gel with petroleum ether/ethyl acetate (9:1). Theresulting product in 4 mL of ethanol was heated to 50° C. Then, toprepare the hydrochloride, 1.5 mL of a 2.9 molar ethanolic hydrochloricacid solution was added dropwise. The precipitate was filtered off,washed twice with 1-mL portions of ethanol and dried.

-   a. Biphenyl-2,4,4′-triamine hydrochloride

Bromo derivative used: 4-bromoaniline

Mass spectrum: MH⁺ 200 (100)

-   b. 2′,4′-Diaminobiphenyl-4-ol hydrochloride

Bromo derivative used: 4-bromophenol

Mass spectrum: MH⁺ 201 (15)

-   c. 2′,4′-Diaminobiphenyl-3-ol hydrochloride

Bromo derivative used: 3-bromophenol

Mass spectrum: MH⁺ 201 (40)

-   d. Biphenyl-2,4-diamine hydrochloride

Bromo derivative used: 4-bromobenzene

Mass spectrum: MH⁺ 185 (100)

-   e. 3′-Methoxybiphenyl-2,4-diamine hydrochloride

Bromo derivative used: 3-bromoanisole

Mass spectrum: MH⁺ 215 (60)

-   f. 4-Benzo[1,3]dioxol-5-ylbenzene-1,3-diamine hydrochloride

Bromo derivative used: 5-bromobenzo[1,3]dioxol

Mass spectrum: MH⁺ 229 (90)

-   g. 4′-Methylbiphenyl-2,4-diamine hydrochloride

Bromo derivative used: 4-bromotoluene

Mass spectrum: MH⁺ 199 (100)

-   h. 4′-Fluorobiphenyl-2,4-diamine hydrochloride

Bromo derivative used: 4-fluoro-1-bromobenzene

Mass spectrum: MH⁺ 23 (100)

-   i. 2′,4′-Diaminobiphenyl-4-carbonitrile hydrochloride

Bromo derivative used: 4-bromobenzonitrile

Mass spectrum: MH⁺ 210 (15)

-   j. 1-(2′,4′-Diaminobiphenyl-3-yl)ethanone hydrochloride

Bromo derivative used: 3-bromoacetophenone

Mass spectrum: MH⁺ 227 (60)

-   k. 4′-Nitrobiphenyl-2,4-diamine hydrochloride

Bromo derivative used: 4-bromonitrobenzene

Mass spectrum: MH⁺ 230 (100)

-   l. 2′-Nitrobiphenyl-2,4-diamine hydrochloride

Bromo derivative used: 2-bromonitrobenzene

Mass spectrum: MH⁺ 230 (100)

-   m. 4′-Trifluoromethylbiphenyl-2,4-diamine hydrochloride

Bromo derivative used: 4-bromotrifluoromethylbenzene

Mass spectrum: MH⁺ 253 (20)

-   n. 2′,4′-Dimethylbiphenyl-2,4-diamine hydrochloride

Bromo derivative used: 2-bromo-m-xylene

Mass spectrum: MH⁺ 213 (60)

-   4′-Chlorobiphenyl-2,4-diamine hydrochloride

Bromo derivative used: 4-bromochlorobenzene

Mass spectrum: MH⁺ 219 (28)

-   p. 4′-Methylsulfanylbiphenyl-2,4-diamine hydrochloride

Bromo derivative used: 1-bromo-4-methylsulfanylbenzene

Mass spectrum: MH⁺ 231 (18)

Examples 2 to 17 Hair Colorants

Hair colorant solutions having the following composition were prepared:

1.25 mmoles of coupler of formula (I) as per Table 1 1.25 mmoles ofdeveloper according to Table 1 1.0 g of potassium oleate (8% aqueoussolution) 1.0 g of ammonia (22% aqueous solution) 1.0 g of ethanol 0.3 gof ascorbic acid to 100.0 g water

Just before use, 50 g of the foregoing coloring solution was mixed with50 g of a 6% aqueous hydrogen peroxide solution. The mixture was thenapplied to bleached hair. After an exposure time of 30 min at 40° C.,the hair was rinsed with water, washed with a commercial shampoo anddried. The resulting color shades are presented in Table 1.

TABLE 1 Developer IV. I. II. III. 4,5-Diamino-1- Coupler 1,4-Di-2,5-Diamino- 2,5-Diamino- (2′-hydroxyeth- Example of formula amino-toluene phenyletha- yl)pyrazole No. (I) benzene sulfate nol sulfatesulfate 2 As per Ex. 1a dark blue dark blue dark blue purple 3 As perEx. 1b dark blue dark blue dark blue purple 4 As per Ex. 1c dark bluedark blue dark blue purple 5 As per Ex. 1d dark blue blue dark bluepurple 6 As per Ex. 1e dark blue dark blue dark blue purple 7 As per Ex.1f dark blue dark blue dark blue purple 8 As per Ex. 1g dark blue darkblue blue purple 9 As per Ex. 1h dark blue dark blue blue purple 10 Asper Ex. 1i dark blue blue blue purple 11 As per Ex. 1j dark blue blueblue purple 12 As per Ex. 1k dark blue blue blue purple 13 As per Ex. 1ldark blue blue blue purple 14 As per Ex. 1m dark blue blue blue purple15 As per Ex. 1n dark blue blue blue purple 16 As per Ex. 1o dark blueblue blue purple 17 As per Ex. 1p dark blue blue blue purple

Examples 18 to 41 Hair Colorants

Hair colorant solutions of the following composition were prepared:

X g of (1,1′-biphenyl)-2,4-diamine [coupler K1 to K4 of formula (I) asper Table 4] U g of developer E8 to E15 as per Table 2 Y g of couplerK11 to K36 as per Table 4  Z g  of direct dye D1 to D3 as per Table 3 10.0 g    of potassium oleate (8% aqueous solution)  10.0 g    ofammonia (22% aqueous solution)  10.0 g    of ethanol 0.3 g   of ascorbicacid to 100.0 g      water

Just before use, 30 g of the foregoing coloring solution was mixed with30 g of a 6% aqueous solution of hydrogen peroxide. The mixture was thenapplied to bleached hair. After an exposure time of 30 min at 40° C.,the hair was rinsed with water, washed with a commercial shampoo anddried. Table 5 shows the coloring results.

TABLE 2 Developers E8 1,4-diaminobenzene E9 2-(2,5-diaminophenyl)ethanolsulfate E10 3-methyl-4-aminophenol E11 4-amino-2-aminomethylphenoldihydrochloride E12 4-aminophenol E13N,N-bis(2′-hydroxyethyl)-p-phenylenediamine sulfate E144,5-diamino-1-(2′-hydroxyethyl)pyrazole sulfate E15 2,5-diaminotoluenesulfate

TABLE 3 Direct Dyes D1 2,6-diamino-3-[(3-pyridinyl)azo]pyridine D26-chloro-2-ethylamino-4-nitrophenol D3 2-amino-6-chloro-4-nitrophenol

TABLE 4 Couplers K1 biphenyl-2,4,4′-triamine hydrochloride K2biphenyl-2,4-diamine hydrochloride K3 2′,4′-diaminobiphenyl-4-olhydrochloride K4 2′,4′-diaminobiphenyl-3-ol hydrochloride K111,3-diaminobenzene K12 2-amino-4-(2′-hydroxyethyl)aminoanisole sulfateK13 1,3-diamino-4-(2′-hydroxyethoxy)benzene sulfate K142,4-diamino-5-fluorotoluene sulfate K153-amino-2-methylamino-6-methoxypyridine K163,5-diamino-2,6-dimethoxypyridine dihydrochloride K172,4-diamino-5-ethoxytoluene sulfate K18 N-(3-dimethylamino)phenylureaK19 1,3-bis(2,4-diaminophenoxy)propane tetrahydrochloride K213-aminophenol K22 5-amino-2-methylphenol K233-amino-2-chloro-6-methylphenol K24 5-amino-4-fluoro-2-methylphenolsulfate K25 1-naphthol K26 1-acetoxy-2-methylnaphthalene K311,3-dihydroxybenzene K32 2-methyl-1,3-dihydroxybenzene K331-chloro-2,4-dihydroxybenzene K344-(2′-hydroxyethyl)amino-1,2-methylenedioxy- benzene.HCl K353,4-methylenedioxyphenol K36 2-amino-5-methylphenol

TABLE 5 Hair Colorants Example No. 18 19 20 21 22 23 Dyes (Dyes ingrams) K1 0.1 0.12 0.05 0.07 0.10 0.12 E8 0.30 E9 0.25 0.3 E15 0.25 0.30.25 K12 0.05 K13 0.05 K31 0.20 0.15 0.20 0.10 K32 0.20 0.10 0.10 K330.20 K21 0.05 K22 0.05 K23 0.05 0.10 0.10 0.10 Coloring results blondblond blond blond blond blond Example No. 24 25 26 27 28 29 Dyes (Dyesin grams) K2 0.1 0.12 0.05 0.07 0.10 0.12 E8 0.30 E9 0.25 0.3 E15 0.250.3 0.25 K12 0.05 K13 0.05 K31 0.20 0.15 0.20 0.10 K32 0.20 0.10 0.10K33 0.20 K21 0.05 K22 0.05 K23 0.05 0.10 0.10 0.10 Coloring resultsblond blond blond blond blond blond Example No. 30 31 32 33 34 35 Dyes(Dyes in grams) K3 0.1 0.12 0.05 0.07 0.10 0.12 E8 0.30 E9 0.25 0.3 E150.25 0.3 0.25 K12 0.05 K13 0.05 K31 0.20 0.15 0.20 0.10 K32 0.20 0.100.10 K33 0.20 K21 0.05 K22 0.05 K23 0.05 0.10 0.10 0.10 Coloring resultsblond blond blond blond blond blond Example No. 36 37 38 39 40 41 Dyes(Dyes in grams) K4 0.1 0.12 0.05 0.07 0.10 0.12 E8 0.30 E9 0.25 0.3 E150.25 0.3 0.25 K12 0.05 K13 0.05 K31 0.20 0.15 0.20 0.10 K32 0.20 0.100.10 K33 0.20 K21 0.05 K22 0.05 K23 0.05 0.10 0.10 0.10 Coloring resultsblond blond blond blond blond blond

Examples 42 to 65 Hair Colorants

Dye carriers in cream form and having the following composition wereprepared:

  X g of (1,1′-biphenyl)-2,4-diamine (coupler K1 to K4 of formula (I) asper Table 4)   U g of developer E8 to E15 as per Table 2   Y g ofcoupler K11 to K36 as per Table 4   Z g of direct dye D2 as per Table 315.0 g  of cetyl alcohol 0.3 g of ascorbic acid 3.5 g of sodium laurylalcohol diethylene glycol ether sulfate, 28% aqueous solution 3.0 g ofammonia, 22% aqueous solution 0.3 g of sodium sulfite, anhydrous  to100.0 g     water

Just before use, 30 g of the foregoing coloring cream was mixed with 30g of a 6% aqueous solution of hydrogen peroxide. The mixture was thenapplied to the hair. After an exposure time of 30 min at 40° C., thehair was rinsed with water, washed with a commercial shampoo and dried.The coloring results are presented in Table 6.

TABLE 6 Hair Colorants Example No. 42 43 44 45 46 47 Dyes (Dyes ingrams) K1 0.6 1.3 1.15 0.15 0.15 0.15 E8 1.5 E13 1.6 0.7 E15 1.8 0.7 0.7K12 0.6 K31 1.10 1.10 1.10 0.40 0.40 0.40 K23 0.05 0.10 0.10 0.10 D20.10 0.10 0.10 Coloring results black black black brown brown brownExample No. 48 49 50 51 52 53 Dyes (Dyes in grams) K2 0.6 1.3 1.15 0.150.15 0.15 E8 1.5 E13 1.6 0.7 E15 1.8 0.7 0.7 K12 0.6 K31 1.10 1.10 1.100.40 0.40 0.40 K23 0.05 0.10 0.10 0.10 D2 0.10 0.10 0.10 Coloringresults black black black brown brown brown Example No. 54 55 56 57 5859 Dyes (Dyes in grams) K3 0.6 1.3 1.15 0.15 0.15 0.15 E8 1.5 E13 1.60.7 E15 1.8 0.7 0.7 K12 0.6 K31 1.10 1.10 1.10 0.40 0.40 0.40 K23 0.050.10 0.10 0.10 D2 0.10 0.10 0.10 Coloring results black black blackbrown brown brown Example No. 60 61 62 63 64 65 Dyes (Dyes in grams) K40.6 1.3 1.15 0.15 0.15 0.15 E8 1.5 E13 1.6 0.7 E15 1.8 0.7 0.7 K12 0.6K31 1.10 1.10 1.10 0.40 0.40 0.40 K23 0.05 0.10 0.10 0.10 D2 0.10 0.100.10 Coloring results black black black brown brown brown

1. Agent for oxidative dyeing of keratin fibers, said agent comprisingat least one developer and at least one coupler, and wherein said atleast one coupler comprises at least one (1,1′-biphenyl)-2,4-diaminederivative compound of formula (I), or a physiologically tolerated saltthereof:

wherein R1, R2, R3, R4 and R5 can be equal or different andindependently of each other, denote hydrogen, a halogen atom, a cyanogroup, a hydroxyl group, a C₁–C₄-alkoxy group, a C₁–C₄-hydroxyalkoxygroup, a C₁–C₆-alkyl group, a C₁–C₄-alkyl thioether group, a mercaptogroup, a nitro group, an amino group, a C₁–C₄-monoalkylamino group, adi(C₁–C₄)-alkylamino group, a trifluoromethyl group, a —C(O)H group, a—C(O)CH₃ group, a —C(O)CF₃ group, an —Si(CH₃)₃ group, aC₁–C₄-hydroxyalkyl group, a C₂–C₄-dihydroxyalkyl group, a —CH═CHR6group, a —(CH₂)_(p)CO₂R7 group or a —(CH₂)_(p)R8 group with p=1, 2, 3 or4, a —C(R9)=NR10 group or a —C(R12)H—NR13R14 group, or two adjacent onesof said R1, R2, R3, R4 and R5 together form an —O—CH₂—O— bridge; R6denotes hydrogen, a nitro group, a —CO₂R7 group or a —C(O)CH₃ group; R7,R9 and R12 are the same or different and, independently of each, otherdenote hydrogen or a C₁–C₄-alkyl group; R8 denotes an amino or nitrilegroup; R10, R13 and R14 are the same or different and, independently ofeach other, denote hydrogen, a hydroxyl group, a C₁–C₄-alkyl group, aC₁–C₄-hydroxyalkyl group, a C₂–C₄-dihydroxyalkyl group or a group of thefollowing formula (III)

and R11 denotes hydrogen, an amino group or a hydroxyl group with aproviso that when R3=NH₂, and R₁=R₂=R₄=H, R₅ is not hydrogen.
 2. Agentaccording to claim 1, wherein at least three of said R1, R2, R3, R4 andR5 denote hydrogen.
 3. Agent according to claim 1, wherein three of saidR1, R2, R3, R4 and R5 denote hydrogen and a remaining two of said R1,R2, R3, R4 and R5, independently of each other, denote hydrogen, amethoxy group, a hydroxyl group, a C₁–C₄-alkyl group, aC₁–C₄-hydroxyalkyl group or an amino group, or, when said remaining twoof said R1, R2, R3, R4 and R5 are adjacent to each other, said remainingtwo of said R1, R2, R3, R4 and R5 together form said —O—CH₂—O— bridge.4. Agent according to one claim 1, wherein said at lest one(1,1′-biphenyl)-2,4-diamine derivative compound of formula (I) isselected from the group consisting of biphenyl-2,4-diamine;4-benzo-[1,3]-dioxol-5-ylbenzene-1,3-diamine;4′-hydroxybiphenyl-2,4-diamine; 4′-aminobiphenyl-2,4-diamine;3′-hydroxybiphenyl-2,4-diamine and 4′-methoxybiphenyl-2,4-diamine. 5.Agent according to claim 1, wherein said at lest one(1,1′-biphenyl)-2,4-diamine devirative compound of formula (I) ispresent in an amount from 0.005 to 20 weight percent.
 6. Agent accordingto claim 1, having a pH from 6.5 to 11.5.
 7. Agent according to claim 1,wherein said at lest one developer is selected from the group consistingof 1,4-diaminobenzene, 1,4-diamino-2-methylbenzene,1,4-diamino-2,6-dimethylbenzene, 1,4-diamino-3,5-diethylbenzene,1,4-diamino-2,5-dimethylbenzene, 1,4-diamino-2,3-dimethylbenzene,2-chloro-1,4-diaminobenzene, 1,4-diamino-2-(thiophen-2-yl)benzene,1,4-diamino-2-(thiophen-3-yl)benzene,1,4-diamino-2-(pyridin-3-yl)benzene, 2,5-diaminobiphenyl;1,4-diamino-2-methoxy-methylbenzene, 1,4-diamino-2-aminomethylbenzene,1,4-diamino-2-hydroxymethyl-benzene,1,4-diamino-2-(2-hydroxyethoxy)benzene,2-[2-(acetylamino)ethoxy]-1,4-diaminobenzene, 4-phenylaminoaniline,4-dimethylaminoaniline, 4-diethyl-aminoaniline, 4-dipropylaminoaniline,4-[ethyl-(2-hydroxyethyl)amino]aniline,4-[di(2-hydroxyethyl)amino]aniline,4-[di(2-hydroxyethyl)amino]-2-methylaniline,4-[(2-methoxyethyl)amino]aniline, 4-[(3-hydroxypropyl)amino]aniline,4-[(2,3-dihydroxypropyl)amino]aniline,1,4-diamino-2-(2-hydroxyethyl)benzene, 1-(2,5-diaminophenyl)-ethanol,1,4-diamino-2-(1-methylethyl)benzene,1,3-bis-[(4-aminophenyl)(2-hydroxyethyl)amino]-2-propanol,1,4-bis-[(4-aminophenyl)amino]butane,1,8-bis-(2,5-diaminophenoxy)-3,6-dioxaoctane, 4-amino-phenol,4-amino-3-methylphenol, 4-amino-3-(hydroxymethyl)phenol,4-amino-3-fluorophenol, 4-methylaminophenol,4-amino-2-(aminomethyl)phenol, 4-amino-2-(hydroxymethyl)phenol,4-amino-2-fluorophenol, 4-amino-2-[(2-hydroxyethyl)amino]methylphenol,4-amino-2-methylphenol, 4-amino-2-(methoxymethyl)phenol,4-amino-2-(2-hydroxyethyl)phenol, 5-aminosalicylic acid,2,5-diaminopyridine, 2,4,5,6-tetraaminopyrimidine,2,5,6-triamino-4-(1H)-pyrimidone,4,5-diamino-1-(2-hydroxyethyl)-1H-pyrazole,4,5-diamino-1-(1-methylethyl)-1H-pyrazole,4,5-diamino-1-[(4-methylphenyl)methyl]-1H-pyrazole,1-[(4-chlorophenyl)methyl]-4,5-diamino-1H-pyrazole,4,5-diamino-1-methyl-1H-pyrazole,4,5-diamino-3-methyl-1-methyl-1H-pyrazole, 2-aminophenol,2-amino-6-methylphenol and 2-amino-5-methylphenol.
 8. Agent according toclaim 1, containg said at least one coupler and said at least onedeveloper in a total amount of 0.005 to 20 weight percent.
 9. Agentaccording to claim 1, further comprising at least one direct-dyeing dyecompound.
 10. Agent according to claim 1, cosisting of a hair colorantcomposition.
 11. A (1,1′-biphenyl)-2,4-diamine derivative of generalformula (II), or a physiologically tolerated salt thereof:

wherein R1, R2, R3, R4 and R5 are the same or different and,independently of each other, denote hydrogen, a chlorine atom, afluorine atom, a cyano group, a hydroxyl group, a C₁–C₄-alkoxy group, aC₁–C₄-hydroxyalkoxy group, a C₁–C₆-alkyl group, a C₁–C₄-alkyl thioethergroup, a mercapto group, a nitro group, an amino group, aC₁–C₄-monoalkylamino group, a di(C₁–C₄)-alkylamino group, atrifluoromethyl group, a —C(O)H group, a —C(O)CH₃ group, a —C(O)CF₃group, an —Si(CH₃)₃ group, a C₁–C₄-hydroxyalkyl group, aC₂–C₄-dihydroxyalkyl group, a —CH═CHR6 group, a —(CH₂)_(p)—CO₂R7 groupor a (CH₂)_(p)R8 group with p=1, 2, 3 or 4, a —C(R9)=NR10 group or a—C(R12)H—NR13R14 group, or two adjacent ones of said R1, R2, R3, R4 andR5 together form an —O—CH₂—O— bridge; R6 denotes hydrogen, a nitrogroup, a —CO₂R7 group or a —C(O)CH₃ group; R7, R9 and R12 are the sameor different and, independently of each other, denote hydrogen or aC₁–C₄-alkyl group; R8 denotes an amino group or a nitrile group; R10,R13 and R14 are the same or different and, independently of each other,denote hydrogen, a hydroxyl group, a C₁–C₄-alkyl group, aC₁–C₄-hydroxyalkyl group, a C₂–C₄-dihydroxyalkyl group or a group of thefollowing formula (III)

 and R11 denotes hydrogen, an amino group or a hydroxyl group; with theproviso that (i) at least one of said R1, R2, R3, R4 and R5 does notdenote hydrogen; (ii) when R3=R5=NH₂, at least one of the said R1, R2and R4 is different from hydrogen, (iii) when R1=R5=H, andR2=R4=tert-butyl, said R3 does not denote an OH group, (iv) whenR2=R3=NH₂, at least one of said R1, R4 and R5 groups is different fromhydrogen, (v) when R3=NH₂ and R1=R2=R4=H, R5 is not hydrogen, (vi) whenR3=NH₂ and R5=H, at least one of R4, R2 and R1 is not hydrogen, and(vii) when R3=R4=NH₂, then at least one of said R1, R2 and R5 isdifferent from hydrogen.